# jwt — Erlang JWT Library #
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[
](https://hex.pm/packages/jwt)
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JWT is a simple authorization token [format](https://jwt.io/) based on JSON.
#### <a name="Installation">Installation</a> ####
If you use rebar (supports both 2 and 3 versions) or mix (Elixir):
```erlang
% in rebar.config for rebar3
{deps, [{jwt}]}.
% or for rebar2
{deps, [{jwt, ".*", {git, "https://github.com/artemeff/jwt", {tag, "0.1.0"}}}]}
```
```elixir
% mix.exs
def deps do
[{:jwt, "~> 0.1"}]
end
```
Or use it as git dependency.
#### <a name="Usage_example">Usage example</a> ####
```erlang
%% Create JWT token
> application:ensure_all_started(jwt).
> Key = <<"supas3cri7">>.
> Claims = [
{user_id, 42},
{user_name, <<"Bob">>}
].
> {ok, Token} = jwt:encode(<<"HS256">>, Claims, Key).
%% or with expiration
> ExpirationSeconds = 86400.
> {ok, Token} = jwt:encode(<<"HS256">>, Claims, ExpirationSeconds, Key).
%% Parse JWT token
> {ok, Claims} = jwt:decode(Token, Key).
%% Issuer specific keys workflow
%% The encoder just knows about itself
> Issuer = <<"iss1">>.
> IssuerKey = <<"Issuer-1-Key">>.
> Claims2 = [
{iss, Issuer},
{user_id, 42},
{user_name, <<"Bob">>}
].
> {ok, Token2} = jwt:encode(<<"HS256">>, Claims, ExpirationSeconds, IssuerKey).
%% Decoder Workflow
%% The decoder knows about all encoder keys (issuer specific)
> IssuerKeyMapping = #{ Issuer => IssuerKey,
<<"iss2">> => <<"Issuer2Key">>}.
> {ok, Claims} = jwt:decode(Token, <<"default-key">>, IssuerKeyMapping).
```
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### <a name="Contributing">Contributing</a> ###
* Fork it
* Create your feature branch (`git checkout -b my-new-feature`)
* Commit your changes (`git commit -am 'add some feature'`)
* Push to the branch (`git push origin my-new-feature`)
* Create new Pull Request
## Modules ##
<table width="100%" border="0" summary="list of modules">
<tr><td><a href="http://github.com/artemeff/jwt/blob/master/doc/jwk.md" class="module">jwk</a></td></tr>
<tr><td><a href="http://github.com/artemeff/jwt/blob/master/doc/jwt.md" class="module">jwt</a></td></tr>
<tr><td><a href="http://github.com/artemeff/jwt/blob/master/doc/jwt_ecdsa.md" class="module">jwt_ecdsa</a></td></tr></table>
